Enable RDP after UART dfu

[alex95]

Hi,

we are experiencing an issue with the STM32G0B0 when RDP level 1 is enabled, following the steps below:

1. Flash the device using J-Link
2. Start the device and let the application set RDP = 1
3. Enter the STM32 ROM bootloader (via UART)
4. Disable RDP protection (perform mass erase)
5. Program new firmware with bootloader
6. Reboot the device and set RDP = 1 again

After this sequence, the device remains locked.
Even if we apply multiple resets using the NRST pin, the device does not recover.
The only way to unlock the device is to completely power-cycle it (turn the power off and on again).

Is it possible to re-enable RDP protection and start the new firmware without removing power from the device?

Thank you for your support.

[Bubbles]

Hi @alex95,

some OB, usually those associated with lifecycle (RDP) require a POR to register (do OB loading). The usual HAL_FLASH_OB_Launch() is not enough.

There's a workaround, POR OBL is not only done on power-cycle, but also on wakeup from Standby and Shutdown low power modes. After programming OB, have the code enter and then leave the low power mode. For the wakeup, you can use for example RTC.

Then the RDP will be modified without need to power-cycle.

BR,

J

[AScha.3]

Hi,

from rm

So seems you have to do a power cycle , as you already found out.